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Biomedical subjects

S Chaudhuri

Publications and source records attributed to S Chaudhuri.

At least 109 records · Page 6Linked to original sources
PubMed1986

Purification and characterization of 3-dehydroquinase from Escherichia coli.

A procedure has been developed for the purification of 3-dehydroquinase from Escherichia coli. Homogeneous enzyme with specific activity 163 units/mg of protein was obtained in 19% overall yield. The subunit Mr estimated from polyacrylamide-gel electrophoresis in the presence of sodium dodecyl sulphate was 29,000. The native Mr, estimated by gel permeation chromatography on Sephacryl S-200 (superfine) and on TSK G3000SW, was in the range 52,000-58,000, indicating that the enzyme is dimeric. The catalytic properties of the enzyme have been determined and shown to be very similar to those of the biosynthetic 3-dehydroquinase component of the arom multifunctional enzyme of Neurospora crassa.

Chromatography, Liquid↗
PubMed1986

The overexpression and complete amino acid sequence of Escherichia coli 3-dehydroquinase.

The enzyme 3-dehydroquinase was purified in milligram quantities from an overproducing strain of Escherichia coli. The amino acid sequence was deduced from the nucleotide sequence of the aroD gene and confirmed by determining the amino acid composition of the overproduced enzyme and its N-terminal amino acid sequence. The complete polypeptide chain consists of 240 amino acid residues and has a calculated subunit Mr of 26,377. Transcript mapping revealed that aroD is a typical monocistronic gene.

Amino Acid Sequence↗
PubMed1985

The purification of shikimate dehydrogenase from Escherichia coli.

A procedure was developed for the purification of shikimate dehydrogenase from Escherichia coli. Homogeneous enzyme with specific activity 1100 units/mg of protein was obtained in 21% overall yield. The subunit Mr estimated by polyacrylamide-gel electrophoresis in the presence of sodium dodecyl sulphate was 32 000. The native Mr, estimated by gel-permeation chromatography on a TSK G2000SW column, was also 32 000. E. coli shikimate dehydrogenase is therefore a monomeric NADP-linked dehydrogenase.

Alcohol Oxidoreductases↗
PubMed1985

Microflora in the trophic ulcers of the foot in leprosy.

Out of 25 cases of trophic ulcers of the foot, 10 (40%) were both aerobic and anaerobic, 14 (56%) only aerobic and one (4%) showed no growth of bacteria. With the exception of two cases (8%) in the aerobic group, all others showed mixed infections. A wide range of bacteria is reported. Topical application of gentamicin and chloramphenicol is recommended, based on the results of in vitro sensitivity.

Bacteria, Aerobic↗
PubMed1984

Evidence from peptide mapping for a human renin zymogen.

Data obtained from peptide mapping of the active and inactive forms of human renin show that there are extensive regions of common sequence in the two forms of the enzyme, and are consistent with the hypothesis that inactive renin is a renin zymogen.

Chromatography, High Pressure Liquid↗
PubMed1983

Lepromin conversion in repeatedly lepromin negative BL/LL patients after immunization with autoclaved Mycobacterium w.

Thirty-two clinically, histopathologically confirmed cases of BL/LL leprosy were rendered bacteriologically negative by prolonged chemotherapy. All of them were negative to Mitsuda and Dharmendra lepromin at the start of study. They were immunized with a single intradermal injection of 5 X 10(7) autoclaved Mycobacterium w and were retested for lepromin reaction 4-6 weeks later. Twenty subjects gave at this time a positive reaction with both Dharmendra and Mitsuda lepromins. The histology of biopsies from converted cases showed mononuclear infiltration in all and granuloma formation in 12 of the 20 positive cases. The stability of the conversion of the patients' lepromin positivity was investigated 6-11 months after immunization with Mycobacterium w. Patients who were earlier converted to a positivity status remained positive in the skin test response to M. leprae. The leukocytes of these patients produced lymphokines on culture with lepromin, causing leukocyte migration inhibition. Patients who did not convert earlier continued to remain anergic to lepromin. These results suggest a conversion, stable for several months, to lepromin positivity caused by immunization with Mycobacterium w in about 60% of BL/LL leprosy patients.

Adult↗
PubMed1982

Corticosteroids and lepromin sensitivity.

Corticosteroids are known to influence the hypersensitivity reaction in a number of diseases involving hypersensitivity of tissues and alter the antigen antibody reactions in vivo. Corticosteroids administered in thirty tuberculoid cases for a period of 3 weeks showed negative response in the lepromin positive cases uniformly thereby proving suppression of cell mediated immunity in tuberculoid cases under the influence of corticosteroids; hence polar concept of tuberculoid type may be under question with continuous and prolonged corticosteroid therapy under necessity.

Adolescent↗
PubMed1979

Affinity chromatography of pig heart fumarase.

2-(5'-Phenylpentyl)fumaric acid was shown to be a competitive inhibitor (Ki 0.5 mM) of pig heart fumarase. After nitration of the aromatic ring, reduction to the amine and diazotization, the acid was attached via azo linkages to a Sepharose 4B-tyramine matrix. The resulting adsorbent was used for the affinity chromatography of crude fumarase, purifications of approx. 20-fold being obtained by specific elution with 0.01 M-citrate.

Animals↗